In planting operations using double disk furrow openers, many soil conditions require the use of scrapers between the two disks of each disk set to remove soil which clings to the inside surfaces or the disks. Removing soil clinging to the inside surfaces ot the disks is particularly difficult in heavy clay soil, and most difficult when planting is done when such soil is wet.
Accumulations of dirt can stop the turning of the disks, which renders them ineffective for proper opening of furrows for seeding. Improper or uneven removal of clods of soil can cause other problems, such as uneven planting depths. Thus, consistent and reliable removal of dirt as the disks turn is essential to proper planting operations. In heavy clay soil, particularly when it is moist, strong solidly-supported substantial scraping structures are required to successfully keep the disks clean and free-running.
It is highly desirable to deposit seeds into the furrows created by double disk sets at positions as far forward as possible, before the furrows have an opportunity to collapse or before dirt particles or clods which are scraped from the disks fall into the furrows and cause unacceptable variations in the depth of planting.
Thus, there is a need on the one hand for substantial solidly-mounted scraper in the position immediately behind the support on which the disks are mounted and a need on the other hand for providing seed deposition at the same fairly forward location.
The prior art includes a number of devices for scraping the inside surfaces of double disk sets. Examples of such prior art structures are disclosed in U.S. Pat. Nos. 4,337,835 (Steilen), 4,206,817 (Bowerman), 1,113,776 (Goetz), 1,264,970 (Pfeifer), 975,499 (Beeman), 785,865 (Davis), and 718,885 (Stephenson).
The devices of the prior art have a number of problems and disadvantages. In some cases, the blades do not consistently remain in engagement with the inside surfaces of the disks. In other cases, they fail in the task of stripping heavy dirt accumulations. Scraper structures of the prior art are often too flimsy or improperly mounted for a heavy stripping task. In some cases, the scraper blades do not respond sufficiently to the separate wobbling motions of the two adjacent disks; that is, scrapers for the two disks sometimes do not operate independently enough to be fully effective.
While a number of problems and disadvantages exist, it is sufficient to note that there is a need for an improved selfadjusting double disk scraper assembly, particularly one which can operate effectively in moist, heavy clay soil.